In 1976, Jefferson County public health director Dr. Carl Johnson and two U.S. Geological Survey scientists reported plutonium concentrations in respirable surface dust downwind of Rocky Flats as high as 380 times their measured background. Published in Science, their research questioned whether measuring plutonium in whole soil adequately captured the potential hazard from fine particles capable of becoming airborne and being inhaled.

CDPHE’s cancer studies provide limited geographic comparisons, but they did not identify exposed residents, reconstruct residential histories, measure individual exposure, or follow people over time. Without that information—and with questions about the study boundaries and Denver metro comparison population—the health effects of Rocky Flats remain unresolved.

Dr. Carl Johnson was Jefferson County's public health director when he began investigating plutonium contamination and cancer around Rocky Flats. His controversial research reported higher cancer incidence in areas with greater measured contamination, and his work became entangled with development, property values and his removal from office. Decades after his death, Johnson is increasingly remembered as an important Rocky Flats whistleblower whose questions about public heal

CDPHE has analyzed cancer-registry data around Rocky Flats for decades. But cancer-registry analysis is not the same as monitoring the long-term health of people who may have been exposed during Rocky Flats operations. Understanding that distinction is essential to understanding what Colorado's cancer studies can—and cannot—tell us.

Existing cancer-registry studies provide useful information about people diagnosed while living near Rocky Flats—but that is not the same as following the people who lived there during historically relevant periods. RFD is advocating for independent research that considers residential history, migration, latency, exposure-informed geography and long-term health outcomes.

Rocky Flats Downwinders is launching the Truth & Transparency Campaign to ask Colorado for clearer disclosure about what existing Rocky Flats cancer studies can—and cannot—tell us, greater data transparency, independent technical review, and research designed to address the health experiences of people who actually lived near Rocky Flats during historically relevant periods.

CDPHE says decades of cancer monitoring have not found elevated rates among residents living near Rocky Flats. But who was actually studied: people present during potential exposure or people living nearby when diagnosed? Our exchange with Colorado’s cancer registry examines this critical distinction

Randy Stafford spent months reviewing decades of Rocky Flats contamination and health studies for the Jefferson Parkway Advisory Committee. His 26-page analysis identified contradictions in study methods, risk models and conclusions—raising a larger question: what would it take to finally conduct the kind of health research Rocky Flats communities need?

A new University of Southern California-led study found higher self-reported rates of autoimmune and endocrine conditions among participants living closer to the Santa Susana Field Laboratory. The findings raise an important question for Colorado: Could similar research help identify health patterns among communities surrounding Rocky Flats?

The 2016 Metro State–RFD Health Survey collected 1,745 community health histories and reported concerning preliminary patterns involving thyroid and rare cancers. The findings were never conclusive—but the study closed before its proposed next steps or a final analysis could be completed.

The Union of Concerned Scientists explains how ionizing radiation can affect the body immediately or contribute to illnesses that emerge years later. Learn why this research matters to communities connected to the nuclear-weapons life cycle, including Rocky Flats.